Package structure and method for forming the same

Abstract

A package structure and method for forming the same are provided. The method includes forming a through substrate via structure in a substrate, and forming a first trench in the substrate. The method includes stacking a first stacked die package structure over the substrate using a plurality of first bonding structures. The first bonding structures are between the substrate and the first stacked die package structure, and a there is plurality of cavities between two adjacent first bonding structures. The method also includes forming an underfill layer over the first stacked die package structure and in the cavities, and the underfill layer is formed in a portion of the first trench. The method further includes forming a package layer over the underfill layer.

What is claimed is: 
     
       1. A method for forming a package structure, comprising:
 forming a through substrate via structure in a substrate; 
 forming a first trench in a first die region of the substrate; 
 forming a second trench in a scribe line region of the substrate, wherein the scribe line region is adjacent to the first die region; 
 stacking a first stacked die package structure over the substrate using a plurality of first bonding structures, wherein the first bonding structures are between the substrate and the first stacked die package structure, and there is a plurality of cavities between two adjacent first bonding structures; 
 forming an underfill layer over the first stacked die package structure and in the cavities, wherein the underfill layer is formed in a portion of the first trench; and 
 forming a package layer over the underfill layer. 
 
     
     
       2. The method for forming the package structure as claimed in  claim 1 , further comprising:
 removing a portion of the substrate, such that the through substrate via structure protrudes from a top surface of the substrate; 
 forming a passivation layer over the through substrate via structure and the substrate; and 
 removing a portion of the passivation layer to expose the through substrate via structure. 
 
     
     
       3. The method for forming the package structure as claimed in  claim 1 , further comprising:
 forming a first connector on the through substrate via structure; 
 forming a second connector below the first stacked die package structure; and 
 bonding the first connector and the second connector to form one of the bonding structures. 
 
     
     
       4. The method for forming the package structure as claimed in  claim 1 , wherein the first stacked die package structure comprises a plurality of memory dies. 
     
     
       5. The method for forming the package structure as claimed in  claim 1 , wherein forming the through substrate via structure in the substrate comprises:
 forming a conductive connector on a front surface of the substrate, wherein a first connector is on the through substrate via structure; 
 bonding the conductive connector to a carrier substrate; and 
 thinning the substrate from a back surface of the substrate. 
 
     
     
       6. The method for forming the package structure as claimed in  claim 1 ,
 forming the package layer into the second trench, wherein the second trench is farther away from the stacked die package structure than the first trench. 
 
     
     
       7. The method for forming the package structure as claimed in  claim 6 , wherein the second trench is deeper than the first trench. 
     
     
       8. The method for forming the package structure as claimed in  claim 1 , further comprising:
 dispersing an underfill material from a first side of the first stacked die package structure to a second side of the first stacked die package structure to form the underfill layer, wherein the first side is closer to the first trench than the second trench, and the first stacked die package structure is between the first trench and the second trench; and 
 filling a portion of the second trench with the underfill material after the portion of the first trench is filled with the underfill layer. 
 
     
     
       9. The method for forming the package structure as claimed in  claim 8 , wherein there is a first distance between a first sidewall of the first stacked die package structure and the first trench, there is a second distance between a second sidewall of the first stacked die package structure and the second trench, and the first distance is greater than the second distance. 
     
     
       10. The method for forming the package structure as claimed in  claim 1 , further comprising:
 forming an interconnect structure on a front surface of the substrate; 
 forming the through substrate via structure on a back surface of the substrate; and 
 forming the first trench on the back surface of the substrate. 
 
     
     
       11. A method for forming a package structure, comprising:
 providing a substrate, wherein the substrate comprises a first die region, a second die region and a scribe line region between the first die region and the second die region; 
 forming a first trench in the first die region of the substrate; 
 forming a second trench in the second die region of the substrate; 
 forming a third trench in the scribe line region, wherein the third trench is between the first trench and the second trench; 
 stacking a plurality of first memory dies over the substrate, wherein the plurality of first memory dies are adjacent to the first trench; 
 stacking a plurality of second memory dies over the substrate, wherein the plurality of second memory dies are adjacent to the second trench; 
 forming an underfill layer between the plurality of first memory dies, the plurality of second memory dies and the substrate, wherein the underfill layer comprises a first portion over the plurality of first memory dies and a second portion over the plurality of second memory dies, and the first portion is separated from the second portion; and 
 forming a package layer on the underfill layer, wherein the package layer is between the first portion and the second portion of the underfill layer. 
 
     
     
       12. The method for forming the package structure as claimed in  claim 11 , further comprising:
 forming a plurality of bonding structures between the first memory dies, wherein there is a plurality of cavities between two adjacent bonding structures; and 
 forming the underfill layer in the cavities. 
 
     
     
       13. The method for forming the package structure as claimed in  claim 11 , further comprising:
 dispersing an underfill material from a first side of the plurality of first memory dies to a second side of the plurality of first memory dies to form the underfill layer, wherein the first side is closer to the first trench than the second trench, and the plurality of first memory dies are between the first trench and the third trench; and 
 filling a portion of the second trench with the underfill material after the portion of the first trench is filled with the underfill layer. 
 
     
     
       14. The method for forming the package structure as claimed in  claim 11 , further comprising:
 separating the plurality of first memory dies and the plurality of second memory dies by performing a cutting process along the scribe line region. 
 
     
     
       15. A method for forming a package structure, comprising:
 providing a substrate, wherein the substrate comprises a first die region, a second die region a scribe line region between the first die region and the second die region and; 
 forming a first trench in the first die region of the substrate; 
 forming a second trench in the second die region of the substrate; 
 forming a third trench in the scribe line region; 
 stacking a plurality of first memory dies over the substrate, wherein the plurality of first memory dies are adjacent to the first trench; 
 stacking a plurality of second memory dies over the substrate, wherein the plurality of second memory dies are adjacent to the second trench; and 
 dispersing an underfill material from a first side of the plurality of first memory dies to a second side of the plurality of first memory dies to form the underfill layer, wherein the first side is closer to the first trench than the second trench; 
 after dispersing the underfill layer, the underfill layer is formed in a portion of the first trench. 
 
     
     
       16. The method for forming the package structure as claimed in  claim 15 , further comprising:
 forming a plurality of bonding structures between the plurality of first memory dies, wherein there is a plurality of cavities between two adjacent bonding structures; and 
 forming the underfill layer in the cavities. 
 
     
     
       17. The method for forming the package structure as claimed in  claim 15 , wherein the first trench is deeper than the second trench. 
     
     
       18. The method for forming the package structure as claimed in  claim 15 , wherein the first trench has a ring-shaped structure when seen from a top-view. 
     
     
       19. The method for forming the package structure as claimed in  claim 1 , wherein a depth of the first trench is different from a depth of the second trench. 
     
     
       20. The method for forming the package structure as claimed in  claim 1 , further comprising forming a third trench in a second die region of the substrate, wherein the scribe line region is between the first die region and the second die region, and a distance between the second trench to the first die region is different from a distance between the second trench to the second die region.